Curing involves hardening of polymer structures by cross-linking polymer chains. Such cured polymer structures have a multitude of applications; they may for instance be utilised in high voltage applications.
The curing process of a polymer composite which is to be formed into a polymer structure traditionally involves injecting the polymer composite into a mould, wherein the mould is heated, thereby shaping the polymer structure from the polymer composite and curing the same. The mould is typically made of steel or a similar material having good thermally conductive properties.
Drawbacks with this curing process are that it is both costly and time-consuming. The moulds in which the polymer structures are moulded and cured are very expensive. Hence each mould is a considerable investment for manufacturers of cured polymer structures. For small production volumes, the cost of the finished polymer structure product is thereby reflected in the mould expenses.
Further, since each mould is very expensive, a manufacturer may not be able to invest in a set of differently sized or shaped moulds, which would provide more flexibility in producing different size polymer structures for different applications, due to the high costs involved. Moreover, the decision of purchasing a new mould requires careful planning for the manufacturer, because a new mould normally takes several months to develop.
Additionally, the mould assembly is subject to high pressures due to the temperature rise during the curing process, putting the mould under constant stress. Thermal expansion of the mould during moulding and curing further increases the costs of the mould assembly, as thermal expansion parameters must be taken into consideration upon construction of the mould assembly.
By utilizing ultra violet (UV) light for curing polymer composites, some of the above drawbacks can be mitigated. As an example, U.S. Pat. No. 5,885,514 discloses an ambient UVL-curable elastomer mould apparatus. The apparatus utilizes injection moulding by injecting an elastomer between two UV-transparent mould plates forming a mould cavity, wherein the mould is irradiated with UV light in order to cure the elastomer in the mould cavity.
However, some of the above problems remain even for production methods involving curing of polymers by means of UV light.